Discharge head having constant force plug retaining member

ABSTRACT

A pressure responsive discharge head in which an expellable plug is disposed in the outlet of a body member having an inlet adapted for connection to a source fo fluid, with the plug being connected relative to the body member in a position preventing the discharge of fluid from the outlet. A connector is provided which applies a constant force to the plug to maintain it in the flow preventing position and which is adapted to release the plug in response to a predetermined fluid pressure existing in the body member.

United States Patent [1 1 Livingston 111 3,812,915 1 1 May 28, 1974 1DISCHARGE HEAD HAVING CONSTANT FORCE PLUG RETAINING MEMBER [75]Inventor: William L. Livingston, Sharon,

Mass.

[73] Assignee: Factory Mutual Research Corporation, Norwood, Mass.

[22] Filed: June 4, 1973 [21] Appl. No; 366,740

[52] US. Cl. 169/38, 169/42 [51] Int. Cl. A62c 37/12 [58] Field ofSearch 169/5, 9, 19, 21, 37-42 [56] References Cited UNITED STATESPATENTS 302,991 8/1884 Fowler 169/40 1,028,940 6/1912 Hunter.....3,314,482 4/1967 Young 3,543,211 11/1970 Dahl 3,561,537 2/1971 Dix etal. 169/38 3,633,676 l/l972 Gloeckler 169/40 3,653,444 4/1972 Livingston169/5 3,684,025 8/1972 Livingston 169/42 3,714,989 2/1973 Gloeckler169/39 Primary Examiner-Robert S. Ward, Jr. Attorney, Agent, orFirm-Lane, Aitken, Dunner &

Ziems [5 7 ABSTRACT A pressure responsive discharge head in which anexpellable plug is disposed in the outlet of a body member having aninlet adapted for connection to a source f0 fluid, with the plug beingconnected relative to the body member in a position preventing thedischarge of fluid from the outlet. A connector is provided whichapplies a constant force to the plug to maintain it in the flowpreventing position and which is adapted to release the plug in responseto a predetermined fluid pressure existing in the body member.

12 Claims, 4 Drawing Figures DISCHARGE HEAD HAVING CONSTANT FORCE PLUGRETAINING MEMBER BACKGROUND OF THE INVENTION The invention relates to adischarge head, and more particularly to a discharge head in which thedischarge of fluid therefrom is controlled in response to the pressureof fluid in the head.

Several applications exist for a discharge head in which the flowtherefrom is controllable in response to the fluid pressure existing inthe head. For example, in applicants U.S. Pat. No. 3,653,444, assignedto the same assignee as the present application, a fixed fireextinguishing system is disclosed which incorporates a plurality ofdirect discharge heads spaced apart greater distances and having largeroutlet orifices when compared to conventional sprinkler heads, to enablegreater quantities of water, or other extinguishant, to be deliveredfrom each head at lower pressures. Preferably, the heads are in the formof wide angle spray nozzles which develop a downwardly directed sprayhaving large size droplets as compared to the droplets produced by theconventional sprinkler heads. According to one of the main features ofthe system disclosed in this patent, the number of nozzles activated todischarge the extinguishant is limited in order to prevent nozzleslocated a relatively long distance from the fire to rob more closelylocated nozzles of valuable extinguishant and extinguishant pressure,and in order to prevent unnecessary water damage.

With this arrangement, the first nozzle actuated by the fire has a muchbetter possibility of extinguishing the tire, because of its ability toretain a predetermined discharge density and the increased ability ofthe larger droplets to penetrate the fire plume of a high challengefire. Of course, if the heat of the fire spreads, a limited number ofadditional nozzles are actuated to help the first nozzle tight the fireand to wet down areas surrounding the fire to provide exposureprotection to inhibit the spread of the fire, with the number ofadditional nozzles that are allowed to be actuated being limited to asmall predetermined number in accordance with the foregoing.

According to a preferred embodiment of the abovementioned system, theabove is achieved by establishing a pressure floor so that a minimumpressure must exist at each nozzle before it will open, with the systembeing designed so that this minimum pressure will not be reached until apredetermined number of nozzles have been opened. The hardware used toestablish the pressure floor includes an expellable plug normallyblocking the outlet of the nozzle and adapted to be expelled from thenozzle to permit extinguishant flow therethrough upon both the fusing ofa conventional temperature responsive device and the presence of a fluidpressure in the nozzles of a magnitude exceeding a predetermined value.In establishing the latter value, a helical compression spring isutilized to latch the expellable plug in a closed position. The designis such that the extinguishant pressure in the nozzle acts upon thehelical spring and has to be of a value to overcome the force of thespring before the expellable plug can be released.

In U.S. patent application Serial Number 346,454, filed Mar. 30, 1973,and also assigned to the same assignee as the present invention, adischarge head is disclosed which incorporates the pressure floorfeature 2. discussed above in adifferent manner. In accordance with thelatter disclosure, the expellable plug is maintained in a flow blockingposition relative to the discharge head by means of a pair of fulcrummedlevers. A fusible link maintains the levers in the plug retainingposition and is responsive to a predetermined temperature for releasingthe levers. A fusible link maintains the levers in the plug retainingposition and is responsive to a predetermined temperature for releasingthe levers. A spring clip is also provided which maintains the levers inthe plug retaining position by virtue of its inherent spring forcewhich, if overcome by the fluid pressure in the body member, releasesthe lever. The spring clip is soldered relative to the levers by meansof a fusible material to provide a failsafe or redundant thermaloverride which, upon the occurrence of the elevated temperature requiredto fuse the latter material, permits the plug to release from the headdespite the fact that the pressure existing in the latter is insufficiento release the plug. v

Although this design proved to be very worthwhile in many respects, itwas difficult to ascertain the precise pressure at which the spring clipwould permit release of the levers and therefore the plug. Also, theclip could not readily accommodate dimensional variations in the variouscomponents of the unit, as well as variations in their relativepositions, which further added to its unpredictability.

SUMMARY OF THE INVENTION It is, therefore, an object of the presentinvention to provide a discharge head of the above type whichincorporates all of the advantages of the heads discussed above, yetwhich enables the plug retaining force to be outlet, said plug memberbeing urged from said flow preventing position by the force of the fluidpressure in said body member, a first linkage member engaging said plugmember, a second linkage member engaging said first linkage member, andconnector means connecting two of said members in a manner to exert apredetermined force against said plug member in a direction opposite tothat of said fluid pressure to maintain said plug member in said flowpreventing position when said fluid pressure is below a predeterminedvalue, said connector means being adapted to release said connectionwhen said fluid pressure exceeds said predeter mined value and permitthe movement of said plug member from said flow preventing position andthe discharge of fluid from said outlet, said connector means beingadapted to exert said predetermined force despite variations in thedistance between its points of connection with said members.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a front elevational view of thedischarge head of the present invention as shown in a fully assembledcondition;

FIG. 2 is a cross-sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a cross-sectional view taken along the 33 of FIG. 1; and

FIG. 4 is a view similar to FIG. I, but depicting an alternateembodiment of the present invention.

DESCRIPTION OF THE PREFERRED I EMBODIMENTS Referring specifically toFIGS. 1-3 of the drawings, the discharge head of the present inventionconsists of a hollow cylindrical body member having an inlet 12 formedat one end thereof and an outlet 14 formed in the other end thereof.

The outer surface of the body member 10 is threaded as shown in 16 nearthe inlet end to permit the head to be connected to a conduit forsupplying fluid, such as water, to the head. By way of example, theconduit could form a portion of a fire extinguishing system, in whichcase the fluid would be in the form of a fire extinguishant, such aswater.

A swirlvane 18 is disposed inside the body member 10 near the inlet end12 thereof for imparting a swirling action to the water as it passesthrough the head in a conventional manner. A portion of the innersurface of the body member 10 is of a reduced diameter to define athroat 20 which extends into a flared portion forming the outlet 14.

As a result of the foregoing arrangement, water introduced into theinlet 12 is swirled as it passes through the body member 10 with itsflow being accelerated as it passes through the throat portion 20 fordischarge in a substantially conical discharge pattern from the outletl4. i

As better shown in FIG. 2, a ring assembly 21 is fastened to the outersurface of the body member 10 near the outlet opening 14 and defines aplurality. of arcuate slots 21a which communicate with the interior ofthe body member 10. As a result, a portion of the water passing throughthe body member 10 will be discharged from the slots 21a in asubstantially radial direction to supplement the main discharge from theoutlet 14. In this manner, the radially extending discharge provides afill in pattern between the main discharge from adjacent body members10.

The outlet 14 is normally closed by means of a cylindrical plug member22 which is retained in the position shown by a pair of levers 24 and26. In its plug retaining position, the lever 24 has a horizontal legportion 24a engaging the plug 22, and a shoulder portion 24b extendingin a groove formed in the outer wall of the body member 10, to supportthe lever relative to the body member.

In a similar manner, the lever 26 has a horizontal extending leg portion26a, and a horizontal shoulder portion 26b also extending in a grooveformed in the body member 10. The horizontal leg portion 26a of thelever 26 is fulcrummed relative to the leg portion 24a of the lever 24about a ball 28 resting on ad adjustable pin 30 supported by thelegportion 26a.

A pair of tabs 32 and 34 extend from the levers 24 and 26, respectively,in a spaced relationship. A fusible line link 36, formed of a materialthat is adapted to fuse, or melt, at a predetermined elevatedtemperature, connects the tabs 32 and 34, and therefore maintains thelevers 24 and 26 in their operative position shown, retaining the plug22 in the outlet 14.

As better shown in FIG. 2, a coiled spring 20 connects the lever 26relative to the body member 10. The spring 40 is in the form of aflexible strip of thin material, such as stainless steel, which has oneend portion coiled around a shoulder 42 formed on the body member 10,and the other end portion attached to a pin 44 extending from the tab 34of the lever 26. This latter attachment is preferably made by forming ahole through the spring 40 near its end, and sizing the pin 44 so thatit extends within the hole to maintain the spring in the position shownin FIGS. 1 and 2.

As a result of the above arrangement, the spring 40 applies a constantforce to the lever 26 urging it into engagement with the lever 24,which, in turn, engages the plug 22 with a predetermined constant force.This constant force is maintained even though, due to tolerancevariations, etc., in the various components, as well as variations intheir relative positions, the distance between the shoulder 42 and thepin 44 may vary considerably. As a result, the spring 40 can becalibrated so that it applies a force of a precise predetermined valueto the plug 22 via the levers 24 and 26 to maintain the plug in theoutlet 14 in the absence of a greater force exerted on the other end ofthe plug 22 by the fluid pressure in the body member 10.

The pin 44 may be of a fusible material, such as solder or the like,which is adapted to fuse at a predetermined elevated temperature of agreater value than that required to fuse the link 36, to enable the plug22 to be discharged from the outlet despite the fact that the waterpressure in the body member 10 does not exceed the force provided by thespring 40, as will be described in detail later.

In operation, the discharge head of the present invention is assembledin its operative condition shown in FIGS. l3 with the levers 24 and 26retaining the plug 22 in the outlet 14, and being maintained in thisposition by means of the link 36 and the spring 40.

Upon the occurrence of a predetermined elevated temperature in thevicinity of the link 36, the latter will melt, and release theconnection between the tabs 32 and 34 and therefore between the levers24 and 26. After this occurs, if the water pressure in the body member10 acting on the plug 22 is sufficient to force the plug outwardly fromthe outlet 14 against the force provided by the spring 40 through thelevers 24 and 26, the end portion of the spring 40 will unwind from theshoulder 42 and permit the levers to fall, and the plug to dischargefrom the outlet.

In the event the fluid pressure in the body member 10 is insufficient toovercome the force of the spring 40 after the link 36 melts, the levers24 and 26 will remain in their operative position shown unless thetemperature proximate to the body member 10 attains the predeterminedvalue which will cause the pin 44 to melt. Upon the occurrence of thislatter condition, the spring 40 will be released from the lever 26, andthe levers 24 and 26 will fall down under the force of the waterpressure acting on the plug, thus permitting the plug, and therefore thewater, to discharge from the outlet 14 and the slots 21a.

it is thus seen that the arrangement of the present invention isrelatively simple in design, has a minimum of parts and yet provides aneffective, precise control of the operation of the head.

The embodiment of FIG. 4 is similar to that of FIGS. 1-3, and identicalstructure will be given the same reference numerals. In the embodimentof FIG. 4, the coiled end portion of the spring 40 extends around a tabor pin 50 formed on the internal wall of the body member 10. The otherend portion of the spring 40 is affixed to the plug 22 at its inner faceas shown.

The pin 50 may be of a fusible material which will melt upon apredetermined temperature occurring in the vicinity of the head of avalue greater than that re quired to melt the link 36, to provide afailsafe release in a manner similar to that provided by the pin 44 inthe embodiment of FIGS. 1-3.

The operation of the embodiment of FIG. 4 is identical to that of FIGS.1-3, with the exception that the levers 24 and 26 will fall upon thefusing of the link 36 regardless of the value of the water pressureexisting in the body member 10. This will then enable the plug 22 to bedischarged from the outlet 14 if the water pressure in the body memberis sufficient to overcome the force provided by the spring 40.

Of course, if the water pressure in the body member 10 is insufficientto permit release of the plug 22 the latter will remain in itsflow-discharge-preventingposition in the outlet 14 unless thetemperature in the vicinity of the head rises to an extent that the pin50 melts which, of course, will permit release .of the plug, asdescribed above..

It is understood that the above embodiments have been described inconnection with a fire protection system by means of example, and thatthe discharge head of the present invention can be used in otherenvironments as well.

Of course, other variations of the specific construction and arrangementof the discharge head disclosed above can be made by those skilled inthe art without departing from the invention as defined in the appendedclaims.

I claim:

1. A discharge head comprising a body member having an inlet for asource of fluid under pressure, and an outlet for discharging saidfluid, a plug member adapted to attain a position in said body member inwhich it prevents the flow of fluid from said outlet, said plug memberbeing urged from said flow preventing position by the force of the fluidpressure in said body member, and connector means connecting said plugmember relative to said body member in a manner to exert a predeterminedforce against said plug member in a direction opposite to that of saidfluid pressure to maintain said plug member in said flow preventingposition when said fluid pressure is below a predetermined value, saidconnector means being adapted to release said connection when said fluidpressure attains said predetermined value and permit the movement ofsaid plug member from said flow preventing position and the discharge offluid from said outlet, said connector means being adapted to maintainthe value of said predetermined force despite dimensional variations insaid members and variations in the relative positions of said members.

2. The head of claim 1 wherein said connector means comprises a strip offlexible material having a coiled portion, said strip of flexiblematerial being fixed relative to said body member and to said plugmember.

3. The head of claim 2 further comprising linkage means for engagingsaid plug member to retain it in said flow preventing position, saidlinkage means including a fusible link responsive to a predeterminedtemperature in the vicinity of saidbody member for releasing saidengagement, said plug member moving from said flow preventing positionupon the existence of both said predetermined temperature and saidpredetermined value of fluid pressure.

4. The head of claim 3 wherein a pin is formed on the interior wall ofsaid body member, said strip of flexible material having one end portioncoiled around said pin and the other end portion attached to said plugmember inside said body member.

5. The head of claim 4 wherein said pin is adapted to fuse at atemperature higher than the fusion temperature of said fusible link topermit release of said plug member despite said fluid pressure beingbelow said predetermined value.

6. The head of claim 1 further comprising linkage means for engagingsaid plug member to retain it in said flow preventing position, saidconnector means comprising a strip of flexible material having a coiledportion, said strip of flexible material being fixed relative to saidbody member and to said linkage means.

7. The head of claim 6 wherein said linkage means includes a first leverengaging said plug member and a second lever engaging said first lever,said strip of flexible material being fixed relative to said body memberand to said second lever.

8. The head of claim 7 wherein said linkage means further comprises afusible link connecting said levers in a manner to maintain said plug insaid flow preventing position, said fusible link being responsive to apredetermined temperature in the vicinity of said body member forreleasing said connection, said plug member moving from said flowpreventing position upon the existence of both said predeterminedtemperature and said predetermined value of fluid pressure.

9. The head of claim 8 further comprising a fusible pin connecting saidstrip of flexible material to said second lever, said pin adapted tofuse at a temperature higher than the fusion temperature of said fusiblelink to permit release of said plug member despite said fluid pressurebeing below said predetermined value.

10. A method for controlling the operation of a discharge head in whicha plug member is disposed in the outlet of said head to normally preventthe flow of fluid therethrough, comprising the steps of exerting apredetermined force against said plug member in a direction opposite tothat of said fluid pressure to maintain said plug member in said flowpreventing position when said fluid pressure is below a predeterminedvalue, releasing said force when said fluid pressure attains saidpredetermined value to permit the movement of said plug member from saidflow preventing position and the discharge of fluid from said outlet,and maintaining the value of said force despite dimensional variationsin said members and variations in the relative positions of saidmembers.

11. The method of claim 10 further comprising the step of exerting anadditional force against said plug member in a direction opposite tothat of said fluid pressure, and releasing said additional force inresponse to the temperature in the vicinity of said head ture in thevicinity of said head exceeding a predeterexceeding a predeterminedvalue. mined value despite the absence of said predetermined 12. Themethod of claim 10 further comprising the value of fluid pressure. stepof releasing said force in response to the tempera-

1. A discharge head comprising a body member having an inlet for asource of fluid under pressure, and an outlet for discharging saidfluid, a plug member adapted to attain a position in said body member inwhich it prevents the flow of fluid from said outlet, said plug memberbeing urged from said flow preventing position by the force of the fluidpressure in said body member, and connector means connecting said plugmember relative to said body member in a manner to exert a predeterminedforce against said plug member in a direction opposite to that of saidfluid pressure to maintain said plug member in said flow preventingposition when said fluid pressure is below a predetermined value, saidconnector means being adapted to release said connection when said fluidpressure attains said predetermined value and permit the movement ofsaid plug member from said flow preventing position and the discharge offluid from said outlet, said connector means being adapted to maintainthe value of said predetermined force despite dimensional variations insaid members and variations in the relative positions of said members.2. The head of claim 1 wherein said connector means comprises a strip offlexible material having a coiled portion, said strip of flexiblematerial being fixed relative to said body member and to said plugmember.
 3. The head of claim 2 further comprising linkage means forengaging said plug member to retain it in said flow preventing position,said linkage means including a fusible link responsive to apredetermined temperature in the vicinity of said body member forreleasing said engagement, said plug member moving from said flowpreventing position upon the existence of both said predeterminedtemperature and said predetermined value of fluid pressure.
 4. The headof claim 3 wherein a pin is formed on the interior wall of said bodymember, said strip of flexible material having one end portion coiledaround said pin and the other end portion attached to said plug memberinside said body member.
 5. The head of claim 4 wherein said pin isadapted to fuse at a temperature higher than the fusion temperature ofsaid fusible link to permit release of said plug member despite saidfluid pressure being below said predetermined value.
 6. The head ofclaim 1 further comprising linkage means for engaging said plug memberto retain it in said flow preventing position, said connector meanscomprising a strip of flexible material having a coiled portion, saidstrip of flexible material being fixed relative to said body member andto said linkage means.
 7. The head of claim 6 wherein said linkage meansincludes a first lever engaging said plug member and a second leverengaging said first lever, said strip of flexible material being fixedrelative to said body member and to said second lever.
 8. The head ofclaim 7 wherein said linkage means further comprises a fusible linkconnecting said levers in a manner to maintain said plug in said flowpreventing position, said fusible link being responsive to apredetermined temperature in the vicinity of said body member forreleasing said connection, said plug member moving from said flowpreventing position upon the existence of both said predeterminedtemperature and said predetermined value of fluid pressure.
 9. The headof claim 8 further comprising a fusible pin connecting said strip offlexible material to said second lever, said pin adapted to fuse at atemperature higher than the fusion temperature of said fusible link topermit release of said plug member despite said fluid pressure beingbelow said predetermined value.
 10. A method for controlling theoperation of a discharge head in which a plug member is disposed in theoutlet of said head to normally prevent the flow of fluid therethrough,comprising the steps of exerting a predetermined force against said plugmember in a direction opposite to that of said fluid pressure tomaintain said plug member in said flow preventing position when saidfluid pressure is below a predetermined value, releasing said force whensaid fluid pressure attains said predetermined value to permit themovement of said plug member from said flow preventing position and thedischarge of fluid from said outlet, and maintaining the value of saidforce despite dimensional variations in said members and variations inthe relative positions of said members.
 11. The method of claim 10further comprising the step of exerting an additional force against saidplug member in a direction opposite to that of said fluid pressure, andreleasing said additional force in response to the temperature in thevicinity of said head exceeding a predetermined value.
 12. The method ofclaim 10 further comprising the step of releasing said force in responseto the temperature in the vicinity of said head exceeding apredetermined value despite the absence of said predetermined value offluid pressure.